Automatic, cyclic, discharge device for rotary, material-processing vessels



H H PICK ETAL\ 2,925,940

AUTOMATIC, cY'cLic, DISCHARGE DEVICE FOR ROTARY, MATERIAL-PROCESSING VESSELS 2 Sheets-Sheet 1 Feb. 23, 1960 Filed May 15, 1959 INVENTORS HANS H. PICK DENARD A. BRANDT HENRY W. FRANZ ATTORNEYS Feb. 23, 1950 PICK ETAL 2,925,940

AUTOMATIC, CYCLIC. DISCHARGE DEVICE FOR ROTARY, MATERIAL-PROCESSING VESSELS Filed May 15, 1959 2 Sheets-Sheet 2 INVENTORS HANS H. PICK DENARD A. BRANDT BY HENRY W. FRANZ ATTORNEYS AUTOMATIC, CYCLIC, DISCHARGE DEVICE FOR ROTARY, MATERIAL-PROCESSING VESSELS Hans H. Pick, Salt Lake City, Utah, Denard A. Brandt, Hayden, Ariz., and Henry W. Franz, Salt Lake City, Utah, assignors to Kennecott Copper Corporation, New York, N.Y., a corporation of New York Application May 1'5, 1959, Serial No. 813,416 6 Claims. Cl. 222-167 This invention relates to discharge devices for materialprocessing vessels, and is concerned with providing a simple and trouble-free device for automatically discharging portions of the contents of a rotary, materialprocessing vessel cyclically as the vessel rotates.

There are many instances in the continuous, industrial processing of various bulk materials in rotating,.materialprocessing vessels, such as rotary kilns, dryers, coolers, and the like, where completely processed material isdischarged from one end of the rotating vessel as partially processed material is advancing toward such discharge end from an opposite, feed or charging end of the vessel. In some instances, it is desirable that a non-oxidizing atmosphere be maintained in the vessel, and, to this end, that the discharge be effected with a minimum entry of air. This is particularly true in the cooling of sponge iron in a so-called Baker cooler following its production from iron pyrite metallurgical concentrates or other iron-oxidc-bearing material.

The Baker cooler is an elongate rotary vessel mounted to rotate on a horizontal axis in a trough of water and provided internally with helical vanes .or lifters for advancing material from one of its ends to the other. 'As the hot sponge iron passes from the feed end of the cooler toward the discharge end, it is cooled to a final discharge temperature of about 150 F. At this discharge temperature, it is stable with respect to oxygen, but during ing below furnace reaction temperature it is subject to oxidation, which necessitates an inert atmosphere within the cooler. If the cooler has an open discharge, as is usual for this equipment, not only is an oxidizing atmosphere established within critical portions of'its interior, but there is a back flow of air into the furnace, which upsets control of secondary air. Without such undesirable back flow of air, the tendency is to draw carbon monoxide into the cooler fromthe furnace, which is desirable in the sense of guarding against an oxidizing atmosphere in critical portions of the cooler.

Heretofore, cumbersome and expensive discharge locks have been employed at the discharge end of the cooler to permit discharge with little entry of air. These have neither been trouble free nor entirely satisfactory in operation.

A principal object of the present invention, therefore, is to provide a new discharge device for a rotary, material-processing vessel, which will permit periodic discharge from the vessel during rotation, without unduly disturbing the processing operation by reason of the entry of air during the periodic discharges of. fully processed material.

Another object is to provide such a device of simple and low cost construction, which shall be positive and trouble-free in operation, require practically no maintenance, operate in accordance 'with rotational cycles, and permit entry of a minimum of air during operation.

An outstanding feature of the invention is the provision I of a resiliently-biased door in the closed, discharge end 2,925,940 Patented Feb. 23, 1960 of the processing vessel at a location remote from the rotative axis thereof, and the provision, further, of an elongate, flexible connector, such as a chain, cable, or cord, connected at one of its ends to the discharge door and anchored at its other end to a stationary support at a location offset from the rotative axis of the vessel and sufficiently remote from the discharge door to hang slack during a major portion of each rotative cycle but to become taut during a minor portion of each rotative cycle and pull the door open against the resilient bias which normally keeps it closed.

In this way, it is possible to vary the length of the period during and the extent to which the discharge door is open by merely varying the off-axis location of the anchorage of the flexible connector. Very little air can enter the vessel during discharge of processed material, because the discharge opening is filled with discharging material while the door is open. Any air that does ent'er flows countercurrent to the discharging material.

Further objects and features of the invention will become "apparent from the following detailed description of the presently preferred specific form thereof illustrated by way of example in the accompanying drawings.

In the drawings:

Fig. 1 represents an end elevation of the discharge nozzle of a Baker cooler which is rotatable in the direction of the appended arrows and is equipped with a discharge device conforming to the invention, the device itself, in material-discharging position, appearing in front elevation, except for the chain flexible connector, which is shown only fragmentarily, the oil-axis anchorage thereof not being shown in this View;

much of its passage through the cooler following cool- Fig. 2, a fragmentary vertical section taken on the line 2-2 of Fig. 1, the chain flexible connector being shown completely, together with its off-axis anchorage, theinternal, discharge'lifters of the cooler not being illustrated;

Fig. 3, a view corresponding to that of Fig. 2, but taken when the cooler is at an advanced position of its rotative cycle, the discharge door being closed andthe chain being slack; and

Fig. 4, a similar view taken on the line 4-4 of Fig. 1 when the cooler is at a still more advanced position commencing at new cycle, the chain being taut and ready to pull the discharge door open as the cooler advances into the new cycle.

Referring to the drawings:

The illustrated Baker cooler is provided with the usual discharge nozzle 10 at the discharge end of an elongate rotary drum (not shown) mounted for rotation in a trough of water (not shown) about its longitudinal axis in well known manner. Hot material to be cooled is charged into the feed end of the drum and gradually travels along the length of the drum to the discharge end, where it is lifted from the drum vproper intothe concentrio and smaller diameter discharge nozzle 10 by helically arranged lifters (not shown) of usual construction.

In many instances, the outwardly flared, annular, discharge lip 11 of the nozzle defines an opening through which air can enter the cooler. In other instances, it is desirable that air be prevented from entering the cooler by closing such opening, as, for example, by an end plate 12 equipped with an explosion cover 13 and an air-excluding, discharge device indicated generally 14.

It is the discharge device with which this invention is concerned.

In the particular preferred form illustrated, the discharge device 14 comprises a door 15 covering a discharge opening 16 in the margin of end closure plate 12. The door is hinged to plate 12 along an edge thereof and is pivoted to be swung outwardly of the cooler and toward axis 17, see ,Fig. 2.

Any suitable hinge arrangement may be employed, but it is convenient to form spaced eye pieces 15a along such edge of the door for mating with a similar eye piece 18 fastened, as by'welding, to end closure plate 12. A pintle 19 completes the hinge attachment of door to cooler in customary manner.

Door 15 is normally maintained tightly closed over discharge opening 16, see Figs. 3 and 4, by resilient means, although it is possible that the arrangement in some forms of the invention may be such as to permit the use of gravity for the purpose. In the present instance, a pair of coil springs 20 are anchored at one set of ends of the termini of a pair of arms 21 which extend outwardly as levers from rigid securement to the hinge eye pieces a, respectively, at opposite lateral sides of door 15. Such springs are anchored at their opposite ends to respective eyes 22, which are fastened to closure end plate 12.

An air-sealing gasket 23 is securely affixed to the inner margins of door 15, so that leakage of air into the cooler is elfectively precluded when the door is closed. An apron plate 24 is preferably provided at the lower margin of discharge opening 16, so as to depend as a discharge lip and as a seat for the lower margin of the door and its portion of gasket 23.- Door 15 overlaps the defining margins of discharge opening 16, as at 25, Fig. 1, so as to provide seating for its lateral and upper margins and corresponding portions of gasket 23. In order to preclude, so far as possible, the entry of air when door 15 is open, it is preferred to provide side plates 26 coextensive with the path of swing of such door and projecting rigidly from securement to end closure plate 12 and discharge lip 24 at opposite lateral sides of the door in snugly fitting relationship therewith.

Opening of discharge door 15 automatically for a brief period during each rotative cycle of the cooler is accomplished by means of an elongate flexible connector, such as chain 27, connected at one end by means of a swivel fitting 28 and eye 29 to that margin of the door which lies opposite the hinge axis thereof, and connected at the opposite end at an off-axis location-to a stationary support 30 by means of a second swivel fitting 28 and eye 29. The length of chain 27 and the position of its off-axis anchorage to support 30, it will be noted, are such as to pull door 15 into open, discharge position, see Fig. 2, during a minor portion of each rotative cycle of 'the cooler. The length of the chain and the off-axis anchorage thereof may be varied to vary the extent of opening of the door and the portion of the rotative cycle during which the door remains open.

In the present instance, it is preferred to open discharge door 15 over an arc of from about to angular degrees at the lower portion of each rotative cycle. To this end, chain 27 is anchored an-appropr-iate distance directly above the projection of cooler rotative axis 17 to support '30. v

When the chain is ready to pull door 15 open, it is taut as shown in Fig. 4. It remains taut as the cooler continues its rotation through the predetermined arc of opening, see Figs. 1 and 2, and then becomes slack, permitting springs 20 to force the door closed, see Fig. 3, throughout the remainder of the rotative cycle.

Whereas this invention is here specifically illustrated and described with respect toa particular preferred embodiment thereof, it should be understood that various changes may be made and various other forms of the device constructed by those skilled in the art without departing from the essential inventive concepts disclosed.

We claim: 7

1. An automatic, cyclic, discharge device for a rotary, material-processing vessel, comprising a door arranged at an ofif-axis location transversely of the rotative axis of the vessel to open and close as the vessel rotates; means normally holding the door closed; an elongate flexible connector attached at one end to said door and at the other end to a'stationary, off-axis anchorage; and respective swivel means attaching said ends of the flexible connector to said door and said anchorage, respectively, the length of said flexible connector being such that said door is pulled .open during a portion of each rotative cycle of the vessel.

2. The discharge device of claim 1, wherein the door is hinged to swing open and closed.

3. The discharge device of claim 2, wherein resilient means normally hold the door closed.

4. An automatic, cyclic, discharge device for an elongate rotary, material-processing drum mounted for rotation about its longitudinal axis and having a closed discharge .end, said device comprising a door disposed marginally of said discharge end and pivoted on a hinge to swing outwardly of the drum toward said axis from a normally closed position; resilient means normally urging said door into said closed position; an elongate flexible connector attached at one end to said door adjacent an edge thereof opposite and remote from said hinge and attached at its other end to a stationary, offaxis anchorage; and respective swivel means attaching said ends of the flexible connector to said door and said anchorage, respectively, the length of said flexible connector being such that said door is pulled open during a portion of each rotative cycle ofthe vessel.

5. The discharge device of claim 4, wherein arms extend rigidly outwardly from opposite lateral sides of the door adjacent the hinge axis thereof, and the resilient means are springs secured to the termini of said arms, respectively, and to the vessel.

6. The discharge device of claim 5, wherein plates project outwardly from the closed discharge end of the drum at opposite lateral sides of the door, said plates being. coextensive with the path of swing of the door and fitting closely with respect to the door to largely exclude air during discharge.

No references cited. 

